Pink bollworm

Pectinophora gossypiella (Saunders, 1844) · formerly or also: Gelechia gossypiella, Platyedra gossypiella

gusano rosado · Spanish, Latin America
lagarta-rosada · Portuguese, Brazil
ver rose du cotonnier · French, West Africa
gulabi sundi · Hindi, South Asia
دودة اللوز القرنفلية (dūdat al-lawz al-qaranfuliyya) · Arabic, Egypt and the Near East

A small moth whose pink-banded caterpillars live hidden inside cotton bolls, eating the seeds and staining the lint. Because the larvae are inside the boll almost from hatching, damage goes unnoticed until bolls are opened. It is one of the most destructive cotton pests worldwide, and in South Asia it overcame two-protein Bt cotton within about a decade.

Pink bollworm larvae inside a cotton boll. Photo: Peggy Greb, USDA Agricultural Research Service, Bugwood.org, Public domain, via Wikimedia Commons.

Type: Insect · Insect (small moth); larva is the damaging stage
Classification: Animalia › Insecta › Lepidoptera › Gelechiidae
Main crops: Cotton, Okra
Found in: South Asia, Africa and the Near East, East and Southeast Asia, Latin America, North America, Oceania
Chemical groups: IRAC 3A, IRAC 1B, IRAC 5, IRAC 6 (mode-of-action groups, not products)
Last reviewed: 2026-10-19

Pink bollworm scientific name, order and family

The scientific name of pink bollworm is Pectinophora gossypiella (Saunders, 1844), in the order Lepidoptera, family Gelechiidae.

Older or alternative scientific names: Gelechia gossypiella, Platyedra gossypiella.

Where it occurs

Thought to originate in the Indian subcontinent or Australia, it spread with cotton seed to almost every cotton-growing region in the early twentieth century. An area-wide programme using sterile moths, transgenic cotton and pheromones eradicated it from the cotton belts of the United States and northern Mexico by 2018.

Region	Status
South Asia	Widespread; resurgent since about 2014 because of resistance to Bt cotton
Africa and the Near East	Widespread in cotton zones, including the Nile valley and West Africa
East and Southeast Asia	Present in cotton regions
Latin America	Present in South America; eradicated from northern Mexico
North America	Declared eradicated from United States cotton in 2018
Oceania	Present in Australia

Symptoms and identification of pink bollworm

The organism

Eggs are tiny, flattened and pearly white, laid singly or in small groups under the calyx and bracts of bolls. Young larvae are white with a brown head; from the third instar they develop broad pink bands across each segment and reach about 12 mm. The adult is a slender grey-brown moth about 8-10 mm long, with narrow, pointed, heavily fringed wings, active at night.

Signs in the crop, stage by stage

Crop stage	What you see
Squaring and flowering	'Rosette flowers': petals held together by the larva's silk so the flower cannot open; damaged squares may shed.
Green boll	A pinhole entry mark that soon closes; inside, a tunnel in the boll wall, damaged locules and seeds, and the larva itself.
Boll opening and harvest	Bolls open badly or partly; lint is stained yellow-brown and weakened; 'double seeds' joined by silk contain resting larvae; exit holes on the boll wall.

Life cycle of pink bollworm

Life cycle of Pink bollworm — diagram drawn by Laisha from the stages below. Durations depend on temperature.

Newly hatched larvae enter flowers or bolls within hours, so they are protected from sprays and predators for most of their life. Mature larvae leave the boll to pupate in the soil or debris, or stay inside seeds. Late in the season many larvae enter diapause inside seeds or soil and survive until the next crop: carry-over in seed, gins and crop residues is how the pest bridges seasons.

Stage	Duration	Notes
Egg	About 4-5 days at 25-30 °C	Under the calyx or on young bolls.
Larva (4 instars)	About 10-14 days inside the boll; months in diapause	Pink bands appear from the third instar.
Pupa	About 7-10 days	In soil, debris or inside the boll.
Adult moth	About 1-2 weeks	Nocturnal; females release a sex pheromone used in monitoring and mating disruption.

Temperature

A generation takes about 25-30 days in warm weather. Short days and cooler nights late in the season trigger larval diapause. Hot, dry soil and extremely high temperatures reduce survival of exposed pupae.

Generations

Usually 4-6 generations a season in irrigated cotton; more where cotton grows for long periods or is ratooned.

Conditions that favour it

Long-duration cotton and late-season crops that keep bolls on the plant, early-sown 'pre-monsoon' cotton that receives moths from carry-over, cotton stalks and unginned seed stored near fields, and ginning mills that release moths. Resistance to Bt cotton and poor refuge compliance have greatly increased outbreaks.

Economic threshold level (ETL)

Because larvae are hidden, thresholds are based on pheromone trap catches, rosette flowers and the percentage of green bolls with live larvae found by opening a sample. Values vary by region and with the cotton's Bt status.

Crop	Threshold	Unit	Crop stage	Region	Source
Cotton	8 moths per trap per night on 3 consecutive nights	male moths per pheromone trap	Flowering to boll development	South Asia	ICAR-Central Institute for Cotton Research pink bollworm management advisories
Cotton	10%	% of flowers (rosettes) or green bolls infested	Flowering to boll development	South Asia	ICAR-Central Institute for Cotton Research pink bollworm management advisories

Thresholds are local. They depend on crop price, control cost, variety and natural-enemy activity, so use the figure your local extension service publishes where one exists.

Damage and yield loss from pink bollworm

Larvae destroy seeds and stain and weaken lint; damaged bolls open poorly and are attacked by boll rots. Losses come from lower seed cotton yield, lower ginning out-turn, lower oil content of seed and downgraded lint. Without control, losses of 20-60% of seed cotton have been reported in outbreak seasons in South Asia, and the pest was historically one of the main yield constraints in the Nile valley.

Monitoring

Install sex pheromone traps from squaring, about 5 per hectare for detection, and read them at least twice a week.
Count rosette flowers on a fixed number of plants weekly.
From about 60 days after sowing, pick 20 green bolls per field at random each week, cut them open and record those with live larvae or exit holes.
Inspect gins and seed stores near fields for moth emergence early in the season.

How to control pink bollworm (integrated management)

Control works best as a sequence: prevent, monitor, then act only when a threshold or a risk forecast says so, using the least disruptive option that works.

Cultural control

Sow within a short, area-wide window and avoid very early sowing that bridges the off-season.
Terminate the crop on time; do not ratoon cotton or leave late bolls standing.
Shred and incorporate or destroy cotton stalks soon after the last picking; do not store stalks with bolls near fields.
Treat or fumigate cotton seed and close ginning premises so carried-over larvae cannot emerge into new crops.

Mechanical and physical control

Pheromone mating disruption, using dispensers that release the female sex pheromone across a whole field or area, reduces mating and has been used successfully on large blocks.
Collect and destroy shed squares, rosette flowers and damaged bolls in small farms.

Biological control

Egg and larval parasitoids (including Trichogramma species, Bracon and Apanteles species) and predators attack eggs and larvae before they enter bolls, but their impact on hidden larvae is limited.
Release of sterile moths, combined with transgenic cotton and pheromones, was central to eradication in North America.

Host resistance

Transgenic Bt cotton expressing Cry1Ac or Cry1Ac plus Cry2Ab controlled the pest for years, but resistance to both proteins evolved and spread in South Asia by the mid-2010s; refuges and newer stacks are required where Bt cotton is grown.
Short-duration, compact cultivars reduce the number of late generations.

Chemical control of pink bollworm — by mode-of-action group only

Laisha names chemical options only by their resistance-committee mode-of-action group (IRAC for insects, mites and nematodes, FRAC for fungi, oomycetes and bacteria, HRAC for weeds), never by active ingredient or product. What is registered differs by country and changes over time; the label and your local plant-protection authority decide what may be used, on which crop, at what rate and with what pre-harvest interval.

Sprays can kill eggs, newly hatched larvae and adults but not larvae inside bolls, so timing against moth peaks matters more than the number of sprays. What is registered differs by country and changes over time; follow the label and your local plant-protection authority.

Scheme	Group	Mode of action	Notes
IRAC	3A	Sodium channel modulators (pyrethroids)	Historically used late season; harmful to natural enemies.
IRAC	1B	Acetylcholinesterase inhibitors (organophosphates)	Resistance reported in some regions.
IRAC	5	Nicotinic acetylcholine receptor allosteric modulators, site I (spinosyns)	Larvicide.
IRAC	6	Glutamate-gated chloride channel allosteric modulators (avermectins)	Larvicide.

Resistance management

Field resistance is documented to Bt Cry1Ac and Cry2Ab in South Asia and to several insecticide groups; rotate groups by generation.
Plant refuges and follow area-wide crop termination dates so a resistant population cannot bridge seasons.

Look-alikes and how to tell them apart

Cotton bollworm — A much larger green-to-brown caterpillar with a large, ragged entry hole and frass outside the boll; never pink-banded.
Spiny bollworms (Earias species) — Larvae with fleshy spines; also bore shoot tips in young cotton and okra.
Boll rots — Fungal or bacterial rots discolour bolls without the internal tunnelling and larvae; they often follow insect damage, so look for an entry hole.

Host range

Cotton (all cultivated Gossypium species) is the main host. Okra, kenaf, roselle and other plants of the mallow family are minor hosts; they can carry populations between cotton seasons in some regions.

What is still uncertain

The geographic origin of the species is still debated.
Effectiveness of newer transgenic stacks against resistant South Asian populations was still being evaluated in the 2020s.

Grow guides for its host crops

How to grow the crop well is the first line of defence. Laisha's free grow guides cover each crop from sowing to harvest:

How to grow Cotton How to grow Okra

Not sure this is what you are seeing?Ask Laisha: describe the symptoms or send a photo, and get a reasoned first read with what to check next — for your crop, your stage and your region.Ask Laisha

Sources

Pectinophora gossypiella (pink bollworm) datasheet — CABI Compendium. https://doi.org/10.1079/cabicompendium.39417
Pectinophora gossypiella (PECTGO) — EPPO Global Database. https://gd.eppo.int/taxon/PECTGO
Pink bollworm: pest profile — IRAC. https://irac-online.org/pests/pectinophora-gossypiella/
Pink bollworm management in cotton (advisories and technical bulletins) — ICAR-Central Institute for Cotton Research. https://cicr.org.in/
Pink bollworm eradicated from US cotton-producing areas — USDA. https://www.usda.gov/media/press-releases/2018/10/19/usda-announces-pink-bollworm-eradication-significantly-saving-cotton

Written by Laisha from the sources above, in its own words. This page is general reference, not a prescription: confirm identification locally and follow the label and your plant-protection authority.